Came here to comment this. I've seen two-lane stop signs and if you imagine traffic on all four sides, just think of the number of other drivers you have to coordinate with if nobody is sure who has the right of way.

I've also seen two lane roundabouts which aren't bad, but now there are roundabouts where you go from two to one, or two to three lanes driving inside the roundabout! Definitely safer than stop signs but the most un-intuitive intersection for new drivers.

Yes, I'd agree. Let's start with reducing those to two lanes then as well :)

mostly agree but as other posters have mentioned I would imagine that any crashes that occur in in mulit-lane 4-ways are likely to be less severe/likely to injure people.